Rubber-mixing mill.



B. 0. HALE.

RUBBER MIXING VHLL.

APPLICATION FILED AUG.I7, r915.

mswma Patented July 4:, 1916.

7SHEETS-SHEET 1.

B. 0. HALE.

RUBBER MIXING MILL. APPLICATION FILED AUG. 17,19l5.

1916. ZSHEETS-SHEET 2.

Patented July 4 Yatented July 1, 1916.

5,0. HALE. RUBBER WXING 'MELL.

APPLICATION FiLED AUG-17,1915.

B. o, HALE.

RUBBER MIXING MILL.

APPLlCATlON FILED AUG-17.1915.

ISHEETS-SHEET 4.

B; L. HALE. RUBEER MiXING MILL. APFLHJATION $11.50 AUGJL 1915.

Patented Juiy 4, 1.916.

YSHEETS-SHEET 5.

B. 0. HALE. RUBBER MIXING MILL.

APPLICATION H'LED AUG. IT, 1915.

iFzatented-July 4, 1916.

3SHETSSHEEI' 6 HALE,

RUBBER :VUQNG irHLL.

APPLICATI FiLiD Tw ns lli ii yi il l n is,

BERNARD 9. HALE E ANSQEIA, CONNECTICUT; ASSIGNOR T0 FAEREL FOUXE'JEEL:

GGMPAZEIY, U33 AllfiONIA, COEFNECTIGUT, A CORPORBEIGEI 0F 331$ MACHINE NEG TIG'UT.

nnnssniinxms MILL.

S'pecificntion of Letters Patent.

Patented July 4t Application filed August 17, 1915. Serial. No, 453%.

mixing coloring material or other com pounds etc, with crude rubbein In niills of this character as at present constructed, one ofthe, rolls is usually driven faster than the other, and us the crude ruhbefr is passed tl'irough the rolls it clings to the slow one, the foreign substance or compound with whi-h the rubber to be mixed being depoh W l between the rolls or upon the rubber clinging to the slow roll, and the surplus material which falls between the rolls being returned to the slow roll by an endless feed apron located beneath f e rolls and running in contact with the slow roll which is usually located at the front of the mill.

Usually the feed apron or belt is supiorted on three or more rollers, and is driven by contact with the slow roll; and pros ision mode for collapsing it when it is desired remove the layer of rubber from the apron driving roll. One of the great objections to this type of mill arises from this colliipsingg of the endless mixer apron which, when collapsed, hangs loosely from the supporting' rollers and falls into the pun located heneuth the, main rolls, where it is likely to become entangled with the batch of rubber being worked. The apron also takes up lumps of dirty matter and impurities w iich have to be removed before the next batch is mixed. Furthermore, when the apron is collapsed or "taken down, it s sometimes :1 diiiicult matter to tighten it up in 21 position .in which it will run perfectly true. in other words, after proper adjustment of the apron on the rollers has been effected, such udjustment is destroyed when the apron is collapsed so that if, under certain cond1- tions, it runs; true on the supporting rollers,

it is like g to he displaced on the rollers'after being coilsosed a d twhtened u a ain so A i? D 7 that it will then wobble from sideto side and give unsatisfactory results,

'Qne of the primary objects of the present invention is to eliminate the drawbacks uhove noted, and to provide a mixing mill in ,wh'ich the apron is maintained in o tuui conditionwhen moved out of contact with i s driving roll. In the inoperative position, the apron is so supported'that it will not fall into the parnond at the same tii'nethe en-'' tire front surface of the apron-driving roll is easily accessible; Furthermore, by keeping the apron t aut when it is moved from operative to inoperative position and-vice versa, the lateral adjustment of the same on the supporting" rollers can be maintained, thereby avoiding the disadvantage above noted. I

Other objects of the invention are to Provide zrmill in which the pun beneath the rolls is substantially unobstructed. by the apron and the other machine parts, and readily accessible for cleahing; and to improve the generixl construction and operation of devices of the class to which theinvention relates.

To theseund other ends, the invention consists in the novel features and combinations of parts to be hereinafter described claimed.

' lnthe accompanying drawings, Figure is a front elevation of a rubbe" mixing mil inhodying my improwinents, with cer'tui parts in section; 2 is a cross section o the mill shown in 1; Fig. 3 is u oerspe'ctive detail ofthe locking device for the apron supporting frame; Fig. 4: a cross 1 section showing mill of somewhat modified type; Fig. 5 a plan View of the nail. i z in d; Fig. 6 is a cross sect? of of still. another type, with certain parts in elevation, showing the apron in the operative position; Fig. 7 is a generally similar View, showing the apron in the inoperative position; Fi 7 is a detail showing the means of supporting one mithe apron rollers; Fig. 8 is a rear eleyetion oi the will shown lRFlgSLii and .7; and 9 is 21 gel SPQClllYQ detail showing a means for preventing wubhling of the apron.

In Figs. l and 2, I have show mill in wnieh the mixing apron is in? i into and out of operative position by hand The frame 20, of ordinaryconstruction, sup ports the usual slow fr'on't roll 21 and fast rear roll that are driven by the usual instrumentalities, which it is not necessary to illustrate. Beneath these rolls is the ordinary pan 23 which may be supported on tie rods 2 connecting the side frames, as shown. The mixing apron 25, which is in the form or an endless belt, is located in part beneath the rolls and between said rolls and the pan; and said apron is supported on suitable supporting rollers 26, 27, 28 and driven by contact with the roll 21. The supporting rollers are so arranged that the apron-curves up over the front surface of the roll 21, which drives the apron in such a direction that any coloring material, etc.

falling between the rolls is caught by the apron and returned toand mixed with the layer of crude rubber which adheres to the slow roll 21. I

In carrying out my invention, I provide means for keeping the apron taut when in the inoperative position, as well as in the operative position, and to this end, the construction may be as follows: Slightly below and in front of the roll 21, I pivot a frame A, comprising a transverse member 2% and supporting arms or side members 30. At their lower extremities, the arms 30 are pivoted to the inner faces of the respective side frames by means such as the bolts 31, whereby the frame is enabled to swing up and down in front of the roll 21. eccentric to the pivot 31 and in rather close proximity thereto, each arm 30 of the frame A is provided with a bearing 32 for the apron supporting roller 27 previously mentioned. Above this roller 27, the frame A carries the roller 26 in similar fashion, the shaft of said roller' b ing journaled in suitable bearings 33 so located "that the roll 26 is slightly beneath the cross member 29 and in parallelism with the roll 27. The third apron supporting roller 28, is located at the lower rear part of the'main frame, and is journaled in movable bearings 34, which are constantly urged in a rearward direction by means of springs 35 adjustable by hand wheels 36. In Fig. 2 I only show the parts 34-, 36 employed at one side of the machino, but it will be understood that a duplicate arrangement is used at the other side. The springs by pulling-rearwardly on the apron, exert a tension thereon which can be regulated by the adjusting wheels 36.

One or more handles 37 are provided on the cross member 29 of the frame A for the purpose of manipulating said frame." Furthermorc, I employ a. lock for holding the frame in the operative position shown in full lines in Fig. 2. By preference, a-lock member 38 comprising a dog pivoted to one of the side frames by a pin 39 has an end portion -10 adapted to engage and disengage At a point a cam shapeareprojection '41 on the correspondinglarm 3b. The movement of the pivoted locking acmber 38 is limited by a stop pin 42 cooperating with a shoulder 43 on the locking member, as shown in Fig. 3.

The operation of'this formof' mill will be obvious for the most part fronffthe foregoworked into the crude rubber and a homogeneous mixtureis produced- During the operation, the lock 38 holds the frame A and the apron tightly in the operative position. lVhen the batch has been properly mixed and it is desired to remove the layer of rubber from the front roll, the locking dog 38 is released in an obvious manner and the frame A is swung down into the position shown by the dotted lines in Fig. 2. By supporting both rollers 26, 27, on the frame A and pivoting the frame at a suitable point, I am enabled to preserve the tautness of the apron while it is being moved from the operative to the inoperative position. In order to produce this result, both rollers 26, 27 have concentric swinging movements about a single pivot, one being located closer to the pivot than the other. It will be observed that when the apron is in the inoperative position, its tightness prevents it from falling down into the pan where it could collect impurities, etc, and that the whole front surface of the roll 21 is readily accessible for cutting off the material adhering to the roll. lVhen another mining operation is to be commenced, the apron may be readily moved into the operative position again by lifting the swinging frame A into the position shown in Fig. 2 and relocking it in that po-;

sition. During this manipulation, the tautness of the apron is still preserved so that the apron w1ll maintain its adjustment on the supporting rollers. Furthermore, it will be observed that when the apron is in the operative position, the pan is wide open at the front end so as to be readily accessible,

" the roller 27, in the operative position of the apron being located considerably above the front end of the pan, and in close proximity to the roll 21, so as to give the apron an upward slant. This enables the pan to be cleaned out readily from the front of the machine because there is a considerable space between it and the apron, and this space is entirely unobstructed.

The springs. 35 aid in preserving the tautmoving the 1 1 J oone by menu 1 2. so;

toohed to counter- 1gb the inoperative p lorol l once of :Ji 7 iii the one of Joe irmi inery iine Connor. the axis of iii oi the center line hos been of the springs as to pm fi onoedgeof the poo.

In the modification the apron tensioiiing by-oountei zveighi's.' apron is supporte corresponding goo tfunoiion m ti'xerajiilorsiki,

The rollers SluE pivoted to the main frame 455 a: oonneoteci tie rod 49. 1. 1e frame A Cam be loo-ire in the operative-position by means ig dog oorresoonoog morally of'o lociio the iooking 5mg 38 prom" oescribefi. The supporting roiier mounted in to to noble gums movable bearings Wordiy and rear'o' (if and the beariiig o oik oooh connected with rope 553 u'p'oror i over a sheave 53 supported 3* o h ookot Mot the lower part of the oohizio. From the sheaves the, ropes I 2 ms rlpwariii over sheares sijppo d on inuokots and thence downward sheaves 57 ot- 5? at. the respective sides of the nmohors. 53' on the counterov. upwardly or r she-o "L the 5G, ooo, i ilAP-Jid over s" frames of the 111ml the frame A, the being comieciod of --o'oes pass nvlse carried .ijorward 2' nos of nation, ts is to pport 13; In: (Fig. 1;; frame he apron the tendency of t: tension the apron o roller 5 reorrmrciil ouilih the .i to? by foo roiis 21 il'nes in 4r) Tm ed sini oly by roieosing puilingf oni'uordlf: on to lower the frame 'ii sition. The pre'gfliniderzso weight of the mow in froi'it'o'f so that tho 'frumo or tiretzie (a uni Morr w on tie rods 66.

n 115 shown.

i) xi o'ii tend to puil the irame A downward inof upward, will be understood; The oounierweights will oilaomnfiiooliy return mum '4", its ioitiii position when tho is again pushed up beyond such I giimry line, will, be manifest. be stated at this lain. that in the drmvings I i. 1:; re not-shown the sub-base on which tho machine is supported, and which, in the form shown in Figs. 'zmd 5,1)1'0'vides for a suflieiont range of movement of the counter-weights. 0f oourso, the counterweight; tension the apron by means of roller 1% when tho apron. is in the inoperative po sition as We}! as woe it is in the operative position. In certain cases only one coonfei v W it' no or be employed (i T and S Show astill further modi fled for-111' of the invention which is appli-:

cable to larger mills owing to the face that the apron shifting meohamsn 1s operatedby power; for examplmo cylinder ond i-msto'n scribed. and ihe apron has substantiolly the some reiotion to the. rolls as previously descrifoed, being iooa-ted betweenisa (ll-011s and Y the pan 65, which, in this case, is sup-ported However, in the form now rmcier discussion, four apron, supporting rollers 67, G8, 69, TO are employed. The rollers 37, 68 are mounted in front of the roll 63 on a frame A oorresponding. substantially so the frame A, hereinbefore described. roller oiso corresponds in location and funouion to the rear tension roller he illbQfOlO described. The fourth or midmooai roiier G9 located inthe loop o, 64:, suit roller being journaie in brooki r or the iottor slants forwarrily and upworciiy from the roller 69 so as tolezwo n scribed. The frame A? comprises side arms "2 pivoted 'o the resneobivo side frames at so that v i as shown in Fig. "I, alliour of the apron supporting roilersmoy be substantially in iioo with email other.

apron is heid tout While in the inoperative axis; of rock arms 74; fixod' to I w exter 1mg; oer

rear portion 0"? will latter the pivots 4:8 the counierweights the apron m a point; benezgth the rolls.

fire position of thoaprom shown mot and of tho pun open and unol mm or in rho examples previously vdeion the frame is swung down,

In this case also, the

m, :s f iii. as While in the operative roller "[0 is mom iod invizezu's .the shaft 80 will be and supported in brackets 76. Rock arms are also fixed on the shaft 75, and are connected by means of springs 78 with brackets 7 9 on the upper art of the frame. The springs 78 tend to pull the arms 7 7 upwardly and thereby shift the arms 7%. rearwardly in order to tension the apron by means of the roller 70. The brackets 7 6 also serve as bearings for a transverse winding shaft 80, carrying at one end a drum 81. A rope 82 is fixed to this drum and passes up over a sheave 8,3 carried by a piston rod 84 of a piston85 working in a cylinder 86. From the sheave 83, the rope 82 passes downward and is attached to any suitable fixed 'point, as indicated for example at 87. It will be obvious that by this arrangement, turned in one direction as the piston is raised, and is free to turn in the other direction when the piston is lowered.

By preference, the cylinder and piston are operated by compressed air, which is adapted to raise the piston for the purpose of rotating shaft 80 in a clockwise direction (Fig. 6). This will raise the frame and apron I into the position shown in Fig. 6, by means of ropes 88 wound on drums 89 on shaft 80 and passing over sheaves 90 on the side frames, the extremities of said ropes being connected to a tie rod 91 connecting the side members of the frame A As long as compressed air is admitted to the cylinder 86, the apron will be held in the operative position by means of the connections described. from the cylinder, gravity, thereby permitting the drum S1 to turn in a counter-cloclnvise direction and releasing the frame A connected with the drums 89 by ropes 88, so that the framewill fall into the position shown in Fig. 7. In this position, the apron isheld taut, out of contact with the pan, and the front roll 63 is freely accessible When another batch is tobe mixed, air is admitted to the cylinder 86 so as to pull up the apron into the operative position in an obvious manner. As long as the air pressure is continued, the apron is tightly held in the operative position. hen large lumps of material pass between the roll 63 and the apron, the roller yields to a certain extent as does also the frame A and as the rollers on the frame are always maintained in parallelism the \vabbling of the apron is prevented.

In the form of the invention lastdescribed, it will be apparent that all four of the apron supporting rollers (two on the main frame and two on the swinging frame) are in line with each other when the apron is down in the inoperative position. l Vhen the apron is up in the operative position, the.

panv is wide open from the front of the machine to a point near the center thereof so However, upon exhausting the air the piston will fall by thatit is easily accessible. for cleaning out, and as the apron rollers and fixtures are independent of the the latter at any time if desired. Located between the mixing rolls and extending rearwardly from the rear mixing roll are guide members or plates 92 which extend along the upper run of'the sides of the machine, and also extend upwardly between the robe (Figs. 6, 7 and 7) for the purpose of keeping the compound on theapron and preventing it from dropping oil the apron at the sides. It will also be noted that by using an air cylinder for raising and lowering the apron, the latter may be cushioned as it moves in either direction.

In order to insure still further against pan, it- 1S easy to emove mixing apron'at the i lateral vibration or wabbling of the apron,

I provide one or more apron supporting rollers with grooves such as the groove 26" in the roller 26 shown in Fig. 9. The apron 25 is provided with a longitudinal series of spaced lugs 92 on its under surface to engage the groove. Preferably, the lugs and "the groove are slightly beveled at the sides. The lugs are so spaced from each other that at least one or more will be in engagement with the groove at any given timeso as to prevent lateral deviation of the apron from a definite oath. The lugs 92 may be made of strips: of leather or other material, and they may be quite deep so as to obtain a tight grip between roll and apron. It has been proposed to use a continuous. strip on the apron engaging the groove in the roller, has to be so thin in order to bend around the roller that it is of little service in keeping the apron in a proper position. By having the lugs 92 separated from each other, as stated, the apron can easily bend around the roller, notwithstanding the depth of the lugs. Various changes in the minor details of the construction may be adopted without departing from the scope of the invention as defined in the claims.

lVhat I claim, is: 1. In a mixing mill, the combination of mixing rolls, an endless feed apron adapted to be moved into and out of cooperation 'with the rolls, and

apron taut when in the inoperative position; substantially as desbrib'ed.

means. for holding the In a mixing mill, the combination of 3. In a mixing mill, the combination of' mixing rolls,"an endless feed apron cooperating therewith, and means for swinging a portion of the apron toward and away in one of the rolls, while maintaining t e to be moved into and out of cooperation tion; substantially as described.

insensiin i sncstsni iaiiy taut; substantially as described.

in a mixing inill, the combination of role, an endless feed apron coonerating therewith and driven by contact with one of said rolls, and means for swing crating therewith, a pan below the apron,

and means for swinging a portion of the apron out contact with one of. said rolls and downward toward the pan to an inoperative position, and forniaintaining said apron taut while in such inoperative posi- 7. ln a mixing mill, the ooinbination of mixing rolls, on cndlessfeed apron cooperating therewithand adapted to befldri'ven by one of said rolls, and means including a pivoted frame with two apron supporting elements carried thereby for holding the apron in a tent condition one of said rolls or in a taut condition away from said last named roll; substantially as describel. i

8. In a mixing mill, the combination of .niixing rolls, an endless leedapron located beneath the same, a framepivoted adjacent one oi said rolls, a plurality oi rollers ournsled in said frame for supporting the apron in contact with said roll, 311(1111821115 for moving the frame away from its cooperating roll into a position wherein the apron is maintained in a tant'condition; substantially as described.

9. in a inixing'niill, the combination of mining rolls, an endless feed apron located beneath the same, a frame located in front of said rolls and pivoted at its lower end portion, and a plurality of apron, supporting rollers jonrnaled in said frame, said rollers adapted-to maintain said apron ina tent condition, irrespective of theswinging movement of said frame; substantially as de scribed.

10. In a mixing mill, the combination of mixing rolls, an. endless feed apron located below the same, and means for swinging a. portion of the apron-loop into and out of contact with one of said rolls, While maintaining the apron substantially taut; sub-' stantislly as described.

11. In mining Qiill, the combination of mininstrolls, an endless iced. apron located rolls, an endless feed apron co'cipbelow the some, means ior swinging a portion or" the apron loop into and ont of Contact vwith one of said rolls, While maintaining the apron means including a Jail)? carrying a plurality of apron supporting rollers and pivoted eccentricslly to said apron supporting rollers; substantially as described.

' 2.121 21 mixing mill, the combination of mixing rolls, an endless teed apron supported beneath the same, and a pan beneath said feed apronJsaid iced apron being entirely independent of said pan and being spaced substantially above the same to leave the end of the pan substantially open and unobstructed; substantially described.

In a mixing inili, the combination of mixing rolls, endless feed apron locatedv beneath the some, and a pan beneath said feed apron, said pan being disposed horizon telly and a portion of so d apron being slanted upward when the apron in the. 0p-

erati've position to allord easy access to the front end oithe pan; substantially as described.

1%. In a mixing mill, the combination of mixing rolls, an endless feed apron, and means for swinging a portion of. the feed apron into andont of contact with the front surface of the front roll a portion of said aoron being slanted upward with respect to the pan when the apron is in'the operative position so as to leave the free end oftlie pan open and ri-zadii accessible, snbstair I tially asdescribed.

l5. ln. a mixing mill, the combination of an endless feed apron, having s longitudinally extending series of hire on the under surface thereof, and apron supporting roller having a {re sverse groove successively engaged by said lug 'tne latter being so spaced that at least one log is engaged substantially taut, said with the groove at any giren'tiine to prcvent wabbling oat-the apron; substantially as described. I

16. In mixing mill, combination of mixing rolls, an endless feed apron adapted tohe mo es. into and out of cooperation with said rolls, means for holding said apron in cooperatii'in with said rolls, and means for holding thc'apron taut when the same is inored out or" cooperation with. the rolls; substantially as described. I

17. In a mixing nail], the combination of mixing rolls, an endless feed apron adaptcd to be moved into and out of contact with one of said rolls, means for holding said apron in contact with one of said rolls, and

means for holding said apron taut when out oi: contact with said roll as Well as when said apron is in contact with the same; substantially as described.

18. In ainizzing mill, the combination of mining cells, an endless :te'ed apron, and means for swinging a portion of the apron mixing rolls, an endless feed apron, means for holding said feed apron in contact with one of said rolls, said apron adapted to be moved out of contact with said roll, means for holding the apron out of contact with said roll, and means for holding the apron taut while out of contact with said roll; substantially as described.

20. In a mixing mill, the combination of mixing rolls, a feed apron, a fluid pressure device to hold said apron in contac with one of said rolls, and means for holding the apron taut when moved out of contact with said roll; substantially as described.

21. In a mixing mill, the combination of mixing rolls, a feed apron normally outof contact with one m said rolls, a fluid pressure device for holding said fee-d apron in contact with said roll, means for operating said fluid pressure device so that the apron moves out of contact with said roll, and means for holding the apron taut when it is moved out of contact with said roll; sub stantially as described.

22. In a mixing mill, the combination of mixing rolls, an endless feed apron cotipen ating therewith and adapted to be driven by one of said rolls, a pivoted frame with at least two apron supporting elements carried thereby for holding the apron in a taut condition against one of said roll or in a taut condition away from said lastnamed roll; and a fluid pressure device for operating said pivoted frame; substantially as described. j

23. In a mixing mill, the combination of mixing rolls, an endless feed apron located I below the same and means for swinging a portion of the apron loop into and out of contact with one of said rolls, while maintaining the apron substantially taut, said means including a frame carrying a plurality of apron supporting rollers and pivoted eccentrically to said apron supporting rollers, and a fluid pressure device acting on said frame to hold the apron in contact with said mixing roll; substantially as described.

24. In a mixing mill, the combination of mixing rolls, an endless feed apron located below the same, and means for swinging a portion of the apron loop into and out of contact with one of said rolls, while main taining the apron substantially taut, said means including a frame carrying a plural ity of apron supporting rollers and pivoted eccentrically to said apron supporting rollers, a fluid pressure device acting on said frame to hold the apron in contact with said mixing roll, and means for controlling the masses operation of said fluid pressure device, said frame and the apron loop supported thereby being free to move the apron out of contact with its cotiperating roll when said controlling means is suitably actuated; substan tially as described.

25. In a mixing mill, the combination of mixing rolls, an endless feed apron supported beneath the same, and guides lo cated beneath the rolls near the respective ends of the latter for preventing the material from falling off the apron at the sides; substantially as described.

26. In a mixing mill, the combination of mixing rolls, an endless feed apron sup ported beneath the same, and guides cxtetiding rearwardly from the rolls along the side edges of the upper run of the apron to prevent the material from dropping off the apron at the sides; substantially as described.

27. The combination of front and rear mixing rolls, an endless feed apron supported beneath the same and having a portion in contact with the front roll, another portion of said apron directed rearwardly and horizontally beneath the rear roll, and guide members located between and beneath said rolls adjacent the edges of the horizontal portion of the apron and extending rearwardly beneath the rear roll along such edges; substantially as described.

28. In a mixing mill, the combination of a frame, front and rear mixing rolls journaled therein, a pan supported in the frame beneath said rolls, a swinging frame pivoted in front of and adjacent the lower portion of the front roll, a roller mounted on the frame beneath and somewhat to the rear of the rear roll, said roller located beneath the pivotalaxis of said swinging frame, rollers carried by said swinging frame and located one above the other, and an endless apron supported on and passing around said firstnamed roller, and supported in contact with the front mixing roll by the upper roller on said swinging frame, the lower roller on said swinging frame being interposed in the loop of the apron, and the apron when in the operative position bein slanted upward over the lower roller of the swinging frame so as to afford access to the front of the pan; substantially as described.

29. In a mixing mill, the combination of a main frame, front and rear mixing rolls journaled therein, a pan supported in the frame beneath said rolls, a swinging rollercarrying frame pivoted to said main frame in front of and adjacent the lower portion of the front mixing roll, an apron suppor ing roller mounted in said. swinging frame above the pivotal axis thereof, a second apron supporting roller mounted in said frame above the first roller, a third apron supporting roller carried by the main frame a main frame, front and rear mixing rolls ournaled therein, a pan supported by sald' frame beneath said mixing rolls, a swinging roller supporting frame pivoted to said main frame in front of and ad acentthe lower portion of the frontmixing roll, apron supporting rollers mounted in said swinging frame above the piyotal axis thereof, an

apron supporting roller mounted on the main frame beneath and to the rear of the main mixing roll, said last-named roller 10- mounted beneathsaid mixing rolls approximately in horizontal alinement with said last-named roller, an endless apron supported. on the several rollers, and means for holding the apron in the operative position; substantially as described.

31. In a mixing mill, the combination of a main frame, front and rear mixing rolls journaled therein, a swinging roller carrying frame pivoted to said main frame in front of. and adjacent the lower portion of the front mixing roll, an apron supporting roller carried by said swinging frame somewhat-above the pivotal axis thereof, a second apron supporting roller carried by said swinging frame adjacent the free extremity thereof, a third apron supporting roller carried by the main frame beneath and to the rear of the rear mixing roll, a fourth apron supporting roller substantially in horizontal alinement with said third apron supporting roller and supportedby the main frame between the first and third rollers, an apron supported on the several rollers and slanted upwardly from the fourtlrroller to the first roller, a pan supported beneath the apron,

and means for holding the apronin the operative position; substantially as described;

32. In a mixing mill, the combination of a main frame, a pair of mixing rolls journaled therein, a swinging apron supporting frame mounted in said main frame, an apron supported: by .said swinging frame and adapted to contact with one of said mixing rolls, a horizontal winding shaft, a vertically arranged fluid actuated cylinder and piston carriedbythe main frame for actuating said winding shaft, and flexible -members adapted to be Wound on said Winding shaft and operatively connected to the sides of said swinging apron supporting frame; substantially as described.

33. In a mixing mill, the combination of a main frame, a pair of mixing rolls jour;

naled therein, a swinging apron supporting frame mounted adjacent the front mixing roll, a horizontal winding shaft mounted'at the rear of the machine and carrying a drum, an upright fluid actuated cylinder and piston carried by the frame, a flexible member attached to the drum of said winding shaft and. connected with said piston,.and flexible members wound on said winding shaft and connected with said swinging frame; substantially as described. 34.. In a mixing mill, the combination of a main frame, a pair of mixing rolls jour naled therein, a swinging apron supporting frame mountedladjacent the front mixing roll, a horizontal winding shaft carried by the main frame, a drum carried by said winding shaft, a rope connecting said-drum.- with a fixed point, an upright fluid actuated cylinder and piston, a sheave on the piston engaging said rope for actuating said winding shaft, and means of connection between amain frame, front and rear mixing rolls journaled therein, an endless feed apron supported beneath said rolls, and guides secured to said ,main' frame and located beneath and between the rolls near the respective ends thereof for preventing the material from falling ofl? the apron at the sides, said guides extending upward from the upper run of the apron into the space between said rolls; substantially as described 1;

In witness whereof, I have hereuntoset my hand on the 14th day of August, 1915.

BERNARD O. HALE. 

